Means for drying extended lengths of thread with infrared lamps



July 20, 1948. c. R. LONG 2,445,443

"BANS FOR DRYING EXTENDED LENGTHS OF THREAD WITH INFRA-RED LAIPS FiledFeb. 10, 1942 2 Sheets-Sheet 1 5-K INVENTOR 6'. K. LONG L BY ,w.ATTORNEY July 20, 1948. an. LONG 2,445,443

' MEANS FOR DRYING EXTENDEDsLENGTHS 9F THREAD WITH INFRA-RED LAMPS FiledFeb. 10, 1942' 2 Sheets-Sheet 2 ,0 I b c (I /H x M I KY m l l v I 6 t l5' a {e I Y mm.

ATTORNEY Patented July 20, 1948 MEANS FOR DRYING EXTENDED LENGTHS OFTHREAD WITH INFRARED LAMPS Charles R. Long, Fort Monroe, Va., assignorto Westinghouse Electric Corporation, East Pittsburgh, Pa., acorporation of Pennsylvania Application February 10, 1942, Serial No.430,226

v4 Claims.

This invention relates to'drying apparatus for textile thread and cordcomprised of natural and/or artificial fibers, and more particularly toslasher-dryer apparatus for the drying of extended lengths of saidthread.

In the textile industry slashing" is a basic operation applied tosubstantially all textile threads, yarns and cords, and involves the twosteps of impregnating the thread with some protecting and strengtheningmaterial in aqueous solution and drying the thread. Many difierent typesof drying apparatus have been devised for use in the second step of thisoperation, but none so far developed have proven entirely satisfactoryin either the quality of the dried product; the speed or productivecapacity of the device; in the flexibilitybf the apparatus for use witha plurality of different thread sizes or thread compositions; or in theautomatic regulation of the same to avoid the deleterious results ofover-drying or underdrying.

One of the objects of the present invention is to provide an improvedslasher-dryer device.

Another object is to provide an electrically heated and electrically.controlled slasher-dryer device.

Still another object is to improve the operation or slasher-dryersandthe quality of the dried thread.

Other objects and advantages will be apparent as the invention is morefully hereinafter complished by radiant heat energy emitted byincandescent filament lamps of the type known in the art as infra-redradiation lamps, and wherein by the appropriate automatic regulation ofthe amount of electric current passing tothe lamps relative to the rateof travel of the thread through the device, the dryer device, per se,may be adapted for use in the drying of a plurality of threads ofdifferent diameters and of different composition and for continuousoperation on threads of indefinite lengths.

Referring to the drawings:

Fig. l is a sectional side elevational view oi the slasher-dryerapparatus of the present inventon;

Fig. 2 is a schematic plan view of the same;

Fig. 3 is a diagrammatic layout of the electrical control and lampenergizing circuit employed in combination with the apparatus of Fig. 1;

Fig. 4 is a schematic diagram illustrating the electricalcharacteristics of the radiant energy generating means of the presentinvention; and

Fig. 5 is a schematic view of a particular type of infra-red radiationgenerating means adapted for use in the present invention.

The slasher-dryer device of the present invention in its broadest aspectconsists of an elongated oven 0 provided in the opposite ends thereofwith inlet and outlet openings X and Y, respectively, for a. pluralityof threads A to be fed continuously therethrough and with means toproject infra-red radiation onto the plurality of threads A as thethreads pass through the oven 0 between the inlet and outlet openingsthereof, with the amount of. said radiation controlled with respect tothe speed of the threads A in such a manner as to prevent over-dryingand under-drying of the threads A. 4

There are many different ways in which this generic inventive idea maybe employed. The arrangement illustrated in thedrawings is one specificembodiment of the same. In the arrangement shown, the means to projectinfrared radiation onto the threads A as they pass through the oven 0comprise a plurality of infrared radiation generating means, such aslamps L, disposed within oven 0 in predetermined horizontal spacedrelation in a plane below that of the openings X and Y, the spacingtherebetween being such as to provide for the projection of infra-redradiation over substantially the entire longitudinal cross-section ofthe oven 0 and means to confine the radiation within a predeterminedspace gap of a cross-sectional area and length enclosing the path oftravel of the threads A within the oven 0. Although shown below, Icontemplate using arrangements in which said lamps are above, as well asin which some are above and some below. The last mentioned arrangementis preferred for materials which do not efiectlvely transmit theradiations and, therefore, require radiant energy on both surfaces forrapid drying.

In the arrangement shown, concentration of the radiation is desirablyobtained by providing an infra-red radiation reflector plate R on theinside face of top T of oven 0, and by employing as infra-red radiationgenerating means a pinrality of lamps L of the type heretofore known inthe art, which are individually provided with reflecting surfaces R Theplate R desirably has a reflecting surface R of aluminum, gold, or othermaterial suitable for efliciently reflecting the generated radiations.By sustaining each lamp L with the reflecting surface R in opposition tothe reflector R with the incandescent filament F therebetween, theplurality of lamps L in close spaced relation form effectively acontinuous reflector R in opposed relation to R I and with thereflectors R and R defining an area within which the infra-red radiationemitted by the lamps L is confined and through which threads A pass.

substantially the same diameter but of difierent lengths are beingpassed through the'dryer, it

-- is frequently necessary to change winding and unwinding reels. Toeffect this change the speed of threads A must be decreased to arelatively slow-rate for a time interval providing for the removal andreplacement of a winding or unwinding reel, during which time interval,unless the heat energy generated within oven is reduced accordingly, thethread A within oven 0 will be subjected to over-drying. Excessiveheating bakes out some of the natural strength of animal or vegetablefibers, and in systems, heretofore employed, there is no rapid flexibleheat control to compensate for any changes made in speed due to materialdefects, inspection, or warp changes.

I have provided for this contingency by arranging the plurality of lampsL in a plurality of lamp banks, numbered I to V inclusive, with theplurality of lamps L in each bank (I to V, inclusive) electricallyconnected to be energized separately and successively and with the totalnumber of lamps L in each bank (I to V, inclusive) selected with respectto a plurality of selected speeds (I to V', inclusive) so that with anygiven minimum speed I of threads A (of any given diameter) the infra-redradiation of the plurality of lamps L in bank I is suflicient to effectthe desired amount of drying in the threads A passing thereover and withany given maximum speed V the total radiation of all the lamps L in thebanks I to V inclusive is sufllcient to effect the desired amount ofdrying in the threads A; the several intermediate speeds II, III and IVbeing selected with respect to the total radiation emitted by banks III,IIIIII, and III IIIIV respectively to accomplish substantially the sameresult.

With the plurality of lamps L thus arranged in a series of banks I to V,I provide a manually operative switch means S adapted to energizesuccessively banks I; banks III; banks III III; banks III-III-IV; andbanks III IIIIV--V, and a, manually operative rheostat means H adaptedto energize motor M actuating drive shaft D in a plurality of speeds Ito V inclusive, wherein speed I' is the desired minimum sliding contactwith the resistance r over substantially the entire length thereof fromdotted position m to dotted position 111*, giving thereby a successionof positions a to e' at which speeds I to V inclusive may be obtained inmotor M.

The two movable elements, lever l and member m of switch S and rheostatH respectively, may be keyed to a rotatable shaft provided with amanually operative rotating means (not shown),

such as a wheel, in such manner as to be shifted simultaneously topositions H to e e', respectively, or to intermediate positions bb',c-c', d-d as desired, the specific arrangement employed being generallyold in the art, and

adapted to be widely modified without essential departure from thepresent invention.

As indicated in the drawings, Fig. 3, the speed of motor M is controlledby rheostat H and the successive energization of the plurality of lampbanks I to V inclusive is controlled by switch means S, manuallyoperative means Im, respectively, in a manner well known in the art.Successive energization of the lamp banks I to V is obtained as follows:

Electric current from supply lines IIIlll' is carried'through switch IIto load circuit lead wires l2-l2'. One lead wire I2 is connected throughconductors Iii-l3 to lever arm 1 of switch S and to member m of therheostat H and by conductor l3 to one side of the armature of motor M,the other side of the armature of motor M being connected back throughconductor 13" and motor'fleld coil 30 through rheostat H to lead wirel2, substantially as indicated. Conductors ll, l5, I6, I! and I8electrically connect lead wire l2 to one side of each of the banks I toV inclusive of lamps L. The other lead wire I2 is connected byconductors Is, 20, 2|, and 22 to the opposite side of each of the banksI to 40 V, inclusive, of lamps L.

speed, speed V' the desired maximum speed, and

speeds II' to IV' are desired intermediate speeds; and provide amechanical interlock means whereby the switch S and rheostat H may besimultaneously actuated manually to positions I to 5 inclusive,corresponding to the same.

The arrangement provided is most simply illustrated in the schematicdiagram of Fig. 3. The switch means S comprises substantially aplurality of arcuate electrically conductive sections a to e inclusivedisposed concentrically about a common axis in a position to besuccessively contacted by said lever on rotation of lever I from dottedline position I to dotted line position 1 The rheostat H comprisesessentially a, resistance r and a moving member 111. adapted to ma e "Toregulate and control the successive energization of the several banks orlamps I to V, inclusive, switch means S is provided with a plurality ofelectrically conducting arcuate sections (a to e inclusive), one foreach of the banks I to V, inclusive, arranged substantially as indicatedto become successively energized upon the rotation of lever e from thedotted position (1") to dotted line position (1 Upon the simultaneousrotation of lever l and member m from circuit open position (l'--m') tofirst circuit closing position (rt-a) by any desired manually operativemeans (not shown), motor. M is energized to a speed I' and the electriccurrent passing through arcuate section it passes 'through conductor 25to solenoid actuated switch means 28, operative to close the electricalcircuit connecting bank I to load circuit lead wires l2-I2', throughconductors H and I9, thereby energizing lamps L of the bank I, theremaining banks II to V, inclusive, remaining de-energized.

When the speed of motor M is increased as by moving member m to positionb, to reduce the field current by increasing the field resistance, leverl is simultaneously moved to a position engaging arcuate section bwhereupon, as may be seen from the electrical connections shown, lampbank II also is energized in substantially the same way as heretoforedescribed for bank I. Further movement of lever arms I and member m tothe relative positions indicated at c-c', dP-d and e "-e', results inthe successive energization of banks III, IV and V in a manner similarto that hereinabove described for banks I and II. It is the art.

- believed apparent that by an appropriate selection of the points a toe on resistance r of rheostat H any desired speed of motor M may beobtained and any desired rate of travel of threads A through oven 0 alsomay be obtained at each of the positions a-a' to H inclusive shown inthe drawings and that the total number of lamps L in each of the banks Ito -V inclusive may be adjusted with respect to the rate of travel ofthreads A to provide the desired amount of infra-red radiation toeil'ect the drying of the threads A'at the determined rate of travel ateach position H to e--e' inclusive.

The particular manner in which lamps L are electrically connected ineach bank I to V inclusive may be widely varied without departure fromthe present invention. In Figs. 3 and 4 I have shown one way to connectthe lamps L in the circuit, which briefly stated is a series-parallelarrangement, wherein two lamps L of the plurality of lamps in each groupof lamps comprising banks I to V inclusive are electrically connected inseries and each pair of series connected lamps L are connected inparallel across the lead wires conducting the supply current to eachbank of lamps I to V inclusive. In this manner, the total number oflamps in each bank I to V inclusive may be readily regulated by cuttingin and out the total number of pairs of series-connected lamps to obtainthe desired heat energy in each bank of lamps. Many alternative ways ofobtaining the same desired result are available in In addition to themechanical convenience of a continuously operating drying means,relatively high rates of production and an improved product with asubstantially consistent and controlled final moisture content, thedried thread product Or other material of the present invention ischaracterized, if thread, by a substantially uniform cross-sectionalarea and rounded contour which difierentiates the same from the prodnetof prior art drying processes, particularly those employing rotatingsteam-heated drums for drying the thread.

The specific structure of oven 0 may be varied widely without departurefrom the present invention, as may also the particular mechanism bywhich the plurality of threads A from unwinding reels (not shown)through the fortifying bath B and through the oven 0 onto winding reelsC, and the specific means for spacing and holding apart the said threadsA in transit through the oven 0, and the various specific means providedto facilitate the mounting and demounting of the winding and unwindingreels. per se, form no part of the present invention. In general, thesese v.

eral means are actuated by a common driving means, such as motor Mthrough gear reduction the oven 0, as by causing a fan F in the due V toreturn the drying air to the oven entrance R, as through an insulatedflue V', after passing through a dehumidifier H. In this way the air,

laden with moisture from the wet material A, may

be dried, while the heat contained therein is reclaimed and used, to atleast some extent, by

convected heat, making it possible to keep the room in which theequipment is located at a cooler temperature due to the desiredinsulation Although I have indicated the drying of the material in oneplane, it will be understood that I do not wish to be limited to this,as fioor space may in some instances be conserved, where it is notundesirable to bend the material being dried, by running said materialdiagonally up and down in a generally inverted V or M shaped oven. Thusthe necessary length of drying space may be secured without the use of acorresponding length of floor space.

It will be understood that although I have disclosed manual means forcontrolling the operation of the motor and lamps, yet I contemplate theuse of automatic means similar to the Taylor moisture analyzers. Such amoisture'controller would operate directly on the yarn or other materialbeingdried, making the machine fully automatic and very sensitive tovariations, thereby vastly improving quality and tending to reducebreakage.

It is believed apparent that the slasher-dryer device of the presentinvention may be widely varied without essential departure therefrom andall such modifications and departures thereof are contemplated as mayfall within the scope of the appended claims. 1

I claim:

1. Apparatus for drying thread and continuous material of a similarnature comprising an oven, inlet and outlet openings in the respective45 end walls of said oven and adjacent the top thereof, a pluralityofinfra-red radiation generatlng lamps disposed in predetermined spacedrelation in a plane below said openings, the total number thereof beingat least sumcient to provide for the projection of infra-red radiationthroughout substantially the entire horizontal cross-section area 01'the oven, reflector means above the level of said inlet and outletopenings and cooperating with said individual lamps to confine theradiations substantially within the space gap therebetween, an insulatedflue connecting the inlet and outlet ends of said oven, 8.

dehumidifier in said flue, means for recirculating the moisture-ladenair passing from said oven outlet through said fiue and dehumidifier andreturningit to the oven inlet, to thereby reclaim some of the heat ofsaid oven, means to feed extended lengths of said continuous materialthrough said oven, means to vary the rate of travel of said materialthrough said oven. and means movable therewith to directly increase ordecrease the amount of infra-red radiations generated by said lamps, asthe rate of travel of said material through the oven is increased ordecreased. 2. Apparatus for drying thread and contin- .uous material ofa similar nature comprising an oven, inlet and outlet openings in therespective end walls of said oven and adjacent the top there- 75 of,lamps generating infra-red radiations in said which would be employedoutside of said air duct I 7 oven, an insulated flue connecting theinlet and outlet ends of said oven, a dehumidifier in said flue, meansfor recirculating moisture-laden air passing from said oven outletthrough said flue and dehumidifier and returning it to the oven inlet,to thereby reclaim some of the heat of said oven, means to feed extendedlengths of said continuous material through said oven, means to vary therate of travel of said material through said oven, and means movabletherewith to directly increase or decrease the amount of infraredradiations generated by said lamps, as the rate of travel of saidmaterial through the oven is increased or decreased.

3. Apparatus for drying threads and continuous material of a similarnature including a supporting frame, a pair of rollers at the enteringend of the frame between which the threads pass, a drum at the oppositeend of the frame on which the threads are wound, electric power meansfor rotating said drum, banks of drying lamp-s supported on said frame,located between said rollers and said drum, and positioned adjacent thethreads for drying the same, said lamps being individually provided withreflecting surfaces and disposed in predetermined spaced relation in aplane below said threads, the total number of said lamps being at leastsuilicient to project infra-red radiation throughout substantially theentire horizontal cross-section area of the apparatus, and reflectormeans above said threads and cooperating with the individual lampreflecting surfaces to confine the radiation substantially within thespace gap therebetween, means to vary the speed of rotation of saiddrum, and means interlocked therewith to automatically make the amountof infra-red radiations generated by said lamps also vary substantiallydirectly proportional to the rate of travel of the threads to obtain thedesired drying efiect.

4. Apparatus for drying threads and continuous material of a similarnature including a supporting frame, a pair of rollers at the enteringend of the frame between which the threads pass, a drum at the oppositeend of the frame on which the threads are wound, an electric mo tor forrotating said drum, banks of drying lamps supported on said frame,located between said rollers and said drum, and positioned adjacent thethreads for drying the same, said lamps being individually provided withreflecting surfaces and disposed in predetermined spaced relation in aplane below said threads, the total number of said lamps being at leastsuflicient to'prolect infra-red radiations throughout substantially theentire horizontal cross-section area of the apparatus, and reflectormeans above said threads 8 and cooperating with the individuallampreflecting surfaces to confine the radiation substantially within thespace gap therebetween, and means comprising a manually-controlledrheostat' in the circuit to the field coil of said motor to control themotor speed and a switch connected to the manual control of saidrheostat 1'01 simultaneously increasing or decreasing the number oflamps energized as the motor speed is increased or decreased bycorrespondingly changing the amount of resistance 01' said rheostat incircuit with said field coil, whereby upon increasing the motor speedthe number of lamps which are energized is simultaneously increased, tothereby directly compensate for said increased speed and avoidunder-drying, and upon decreasing the motor speed the number of lampswhich are'energized is simultaneously decreased, to thereby avoidover-drying.

CHARLES R. LONG.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,023,316 Hurwitz Apr. 16, 19121,228,225 Lynoh May 29, 1917 1,432,729 Plnder Oct. 17, 1922 1,463,923Nelson Aug. 7, 1923 1,571,282 Leculier Feb. 2, 1926 1,683,833 ManeschiSept. 11, 1928 1,802,407 Danninger et a1. Apr. 28, 1931 1,956,737 Walkeret a1. May 1, 1934 2,034,270 Reading Mar. 17, 1936 2,057,776 Groven Oct.20, 1936 2,065,070 Hanson Dec. 22, 1936 2,156,352 Peterson May 2, 19392,186,067 Groven Jan. 9, 1940 2,204,603 Kline at al June 18, 19402,220,928 Kienle et al Nov. 12, 1940 2,236,754 Gurwick Apr. 1, 19412,268,986 Hess et al. Jan. 6, 1942 2,269,236 Wellmar Jan. 6, 19422,281,184 Dykstra et a1. Apr. 28, 1942 2,308,239 Bell Jan, 12, 19432,355,391 Nelson et al. Aug. 8, 1944 2,420,399 New May 13, 1947 OTHERREFERENCES Quicker Drying with Lamps, Beggs, pages 88, 89 in "FactoryManagement and Maintenance, July 1939 issue.

"Infra-Red Does the Trick, pages 124 to 127 in Scientific American,Sept. 1941 issue.

